He could have the Sharingan's ability to copy and predict moves. Also, the Byakugan's near - 360 - degree vision would be really cool. And if he had the Rinnegan, he could use all kinds of powerful jutsu like the Deva Path's gravity manipulation.
One interesting ability would be combining the Uchiha's fire - based jutsu from the Sharingan with the Uzumaki's chakra - enhancing abilities. This could create some really powerful and unique fire - type attacks. And with the Hyuga's Byakugan, he could precisely target weak points in an opponent's chakra system while using his own powerful chakra punches. He might also be able to use the Nara's shadow - binding techniques in a more enhanced way with his newfound power boost.
One interesting combination could be the Uchiha bloodline with the Uzumaki bloodline. The Sharingan from the Uchiha and the massive chakra reserves and sealing abilities of the Uzumaki could create a really powerful Naruto. Another could be the Hyuga bloodline combined with the Uzumaki. The Byakugan's visual prowess along with the Uzumaki's chakra would give Naruto enhanced perception and more chakra to use for powerful jutsu.
In this fanfiction, the Sharingan from the Uchiha clan is an obvious choice. It has so many abilities like the ability to copy jutsu and predict movements. Naruto could become even more of a prodigy if he absorbs it. Also, the Aburame clan's ability to control bugs could be quite interesting. Naruto could use bugs for reconnaissance or even in combat in ways that are different from his normal fighting style. And the Inuzuka clan's connection with animals, if Naruto could absorb that bloodline, he might be able to form a stronger bond with his summons or other animals in the wild.
He could have the ability to create elemental shields. For example, using earth to create a solid shield against physical attacks and then overlaying it with water to make it more resistant to fire - based attacks.
The new combinations of abilities from the six bloodlines make it interesting. It allows for unique character development and power - ups that we don't see in the original Naruto story.
In some fanfictions, one could be the Sharingan, which gives abilities like seeing chakra and predicting moves. Another might be the Byakugan, with its great vision powers. And the third could be something unique like the Ketsuryugan, which could have powers related to blood manipulation.
Well, it changes a great deal. With all bloodlines, Naruto becomes an extremely powerful force. He can combine the unique abilities of different clans. For example, he could use the Sharingan's predictive abilities along with his own Uzumaki stamina and chakra reserves. This would make him almost unbeatable in combat against most foes. Enemies who were previously a threat would find it much harder to face him as he could counter their techniques with a wide variety of bloodline - based powers.
One possible plot could be Naruto suddenly awakening all bloodlines and using them to defeat a new, extremely powerful enemy that threatens the entire ninja world.
He could potentially have a made - up doujutsu bloodline. For example, a doujutsu that allows him to see the future for a short period. This would give him an incredible advantage in battles as he could anticipate his opponents' moves far in advance. Another option could be a doujutsu that lets him manipulate the elements he sees with his vision, like being able to freeze water just by looking at it in a way.
One interesting aspect of Naruto all bloodlines fanfiction is the exploration of unique abilities. For example, some fanfictions might focus on a character with a rare bloodline having to hide their powers in a village that fears them. This can lead to really intense storylines full of mystery and self - discovery.